Thermostat.



G. P. WILD.

THERMOSTAT.

APPLIOATION FILED DBO. 2, 1910. RENEWED NOV. 6, 1911.

Patented Dec. 26, 1911.

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' v ATTORNEYS patents, Nos. 976,748 and 976,750,

' UNITED Srazrpsgagnnr orrron.

GIIN'IHER PHILIP 'WILD, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 FRED- ERICK W. SCHMIDT, OF PHILADELPHIA, PENNSYLVANIA.

THERIVIOSTAT.

Specification of Letters Patent.

Application filed December 2, 1910, Serial No. 595,284. Renewed November 6, 1911. Serial No. 658,874.

To all whom it may concern:

- Be it known that I, Gtimnnn Prue-n l/VILD, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Thermostat, of which the following is a specification.

My invention consists of certain improvements in a thermostat particularly adapted for use in a controlling apparatus for charging storage batteries, such as disclosed in granted to Frederick lV. Schmidt, on the 22d day of November, 1910.

It further consists of a thermostat capable of functions and possessed of properties similar to those performed and possessed by the thermostats for which Letters Patent Nos. 976,747 and 976,749, were granted to Frederick lV. Schmidt, on the 22d day of November, 1910. v

It further consists of a thermostat having a casing composed partly of elcctricall y conductive and partly of electrically non-conductive but acid-resisting materials.

It further consists of a thermostatfor such purpose and in which the casing is composed of an acid-resisting and non-con: cluctive material having electrodes of acid resisting and electrically conductive material extending through the casing to the elements of the thermostat.

It further consists of other novel features of construction, all as will be hereinafter fully set forth.

For the purpose of'illnstrating my inven-' .tion, I have shown in the accompanying drawings one form thereof which is at present preferred by me, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be varitiusly arranged and organized and that my invention is not limited to the precise arrangement and organization of these instrlnnentalities as herein shown and described.

Said drawing represents a longitudinal section ofa thermostat embodying my invention.

The thcrnmstat consists of a metallic baseplate, 1, usually'of brass, having a short post, 2, at one end, into which one end of a composite metal thermostat-bar, 3, is secured. The free end of said bar has a contact-point, 4:, preferably of a metal fusible at a high temperature, only, which registers and may have contact, when the bar is flexed owing to the difference in the co-ellicients of expansion of. the two metals from which the bar is formed, with a contact-point, 5, of

the same metal and secured to the end of a contact-screw, 6, threaded, to be adjusted with its point nearer to or farther from the contact-point of the thermostat-bar, in a yoke or bracket, 7, secured upon but insulated from the base-plate. The base-plate and thermostat is inelosed within the body,

8, of a casing, preferably of rectangular form, and having its top closed by a cover, 9. secured with its edges in rabbets, 10, in the upper edges of the sides of the casing by suitable cement or similar closure, ill, rendering the joints between the cover and sides liquid proof. The casing and cover are formed from glass,'hard rubber or any similar acid-resisting and electrically noncomlucting material; .liy acid-rcsisting material, I mean material capable of resistjug acids of the strength of the solnlimis usually employed in storage batteries. Parts of the bottom or walls of the casing are formed from acid-resisting but electrically conductive material, and I prefer to make such parts in the form of plugs or inserts, 12, of lead, which inserts are in electrical. contact with the base of the thermostat and, through said base, with the thermostat bar.

The cover of the casing has a rahbeted opening, '15), into which fits a shouldered plug, 14., and said opening and plug register with the head of the contact-surew, so that the latter may be adjusted from without, by removing the plug. Said plug is preferably secured fluid-tight in its opening by a suitable ccment, indicated by the numeral 15, which is fusible or soluble so as to be softened or dissolved to aghnitof the plug beingrcmoved without disturbing the ren'iaindor of the casing. A binding screw, 16, is inserted with its lower end through an opening, 17, in the cover of the casing. and has a flange, 18, at about its middle. Said flange has annular ribs, 19, upon its under side, which intermesh with similar annular ribs, 20, forming a seat upon the upper side or cover of the casing, and a gasket, 21. of rubberor ribbed flange and the seat.

similar yielding material, resistant to the battery solution, is clamped between the Similar annular ribs, 22, form a seat on the underside of the topor cover of the casing, and a yielding gasket, 23, is clamped against such seat by a washer, 2%, having registering annular ribs, 25, and held in place by a nut, 26, upon the lower end of the screw.

A wire, 27, or similar conductor is secured ;to the thermostat contact-screw and to the binding-screw or post 16, and a binding-nut,

28., of acid-resisting and insulating material, fits upon the upper end of the bindingpost. The binding screw and the washer 24 are formed from an electrically conductive and acid-resisting metal, and it is known that in practice, pure and unalloyed silver is the preferable material. with a filling, 29, of an insulating and heatconducting liquid, such as a liquid hydrocarbon, which makes a satisfactory and practical liquid, by means of which the elements Within the casing are properly insulated, arcs formed between the contact points will be, extinguished, and heat will be conveyed from the exterior of the casing to the thermostat bar.

, Having thus described my invention, What I claim as new and desire to secure by Letters Patent, is

1. A thermostat having an inclosing casing composed partly of electricallyconductive and acid-resisting material extending from the exterior and in electrical connection with one contact of the thermostat and the remaining portion of said casing being The casing is filled of electrically non-conductive but acid-resisting material.

2. A thermostat having an inclosing casing of acid-resisting and electrically nonconductive material, and externally exposed inserts in such casing of acid-resisting and electrically conductive material and connected to one contact of the thermostat.

3. A thermostat having an inclosing casing of acid-resisting and electrically nonconductive material, acid-resisting and electrically conductive externally exposed inserts in said casing, and two contacts, one of which is electrically connected to said externally exposed inserts.

4C. In a thermostat, an inclosing casing of acid-resisting and electrically non-conductive material, electrically conductive inserts in a wall of said casing, a base plate within the casing and electrically connected to said insert-s,a thermostat bar upon said base-plate and having acontact-point, a contact-screw insulated from the base-plate, a bindingpost insulated from the casing, and a conductor connected to the binding-post and the contact-screw.

5. A thermostat having an inclosing acidresisting casing of single thickness, part of the outer surface of which is electrically non-conductive and part of such surface is electrically conductive and electrically connected to one contact of the thermostat.

GUNTHER PHILIP WILD.

lVitnesses:

C. D. MGVAY, F. A. NEWTON. 

